Page 53 - UK SERA Standardises European Rules of the Air Regulations (Consolidated) January 2022

SERA - Standardised European Rules of the Air

SECTION 13 SSR TRANSPONDER

Reference Description
SERA.13001 Operation of an SSR transponder
(a) When an aircraft carries a serviceable SSR transponder, the pilot shall operate the
transponder at all times during flight, regardless of whether the aircraft is within or outside
airspace where SSR is used for ATS purposes.
(b) Pilots shall not operate the IDENT feature unless requested by ATS.
(c) Except for flight in airspace designated by the competent authority for mandatory operation
of transponder, aircraft without sufficient electrical power supply are exempted from the
requirement to operate the transponder at all times.
SERA.13001 GM1 Operation of an SSR transponder
Pilots of aircraft engaged in formation join-ups are expected to continue operating the transponder until
established in formation. Once established in formation, all except the lead aircraft should be
instructed to ‘squawk standby’.
SERA.13001(c) GM1 Operation of an SSR transponder
Pilots of non-powered aircraft are also encouraged to operate the transponder during flight outside
airspace where carriage and operation of SSR transponder is mandatory.
SERA.13005 SSR transponder Mode A code setting
(a) To indicate that it is in a specific contingency situation, the pilot of an aircraft equipped with
SSR shall:
(1) select Code 7700 to indicate a state of emergency unless ATC has previously
directed the pilot to operate the transponder on a specified code. In the latter case, a
pilot may nevertheless select Code 7700 whenever there is a specific reason to
believe that this would be the best course of action;
(2) select Code 7600 to indicate a state of radio-communication failure;
(3) attempt to select Code 7500 to indicate a state of unlawful interference. If
circumstances so warrant, Code 7700 should be used instead.
(b) Except in the cases described in (a) above, the pilot shall:
(1) select codes as instructed by the ATS unit; or
(2) in the absence of ATS instructions related to code setting, select code 2000 or
another code as prescribed by the competent authority; or
(3) when not receiving air traffic services, select code 7000 in order to improve the
detection of suitably equipped aircraft unless otherwise prescribed by the competent
authority.
(c) When it is observed that the code shown on the situation display is different from what has
been assigned to the aircraft:
(1) the pilot shall be requested to confirm the code selected and, if the situation
warrants, to reselect the correct code; and
(2) if the discrepancy between assigned and displayed codes still persists, the pilot may
be requested to stop the operation of the aircraft's transponder. The next control
position and any other affected unit using SSR and/or multilateration (MLAT) in the
provision of ATS shall be informed accordingly.
SERA.13005(a) GM1 SSR transponder Mode A code setting
If a pilot has selected Mode A Code 7500 and has been requested to confirm this code by ATC, the
pilot should, according to circumstances, either confirm this or not reply at all. If the pilot does not
reply, ATC should take this as confirmation that the use of Code 7500 is not an inadvertent false code
selection.
SERA.13005(c) AMC1 SSR transponder Mode A code setting
When requested by ATC to confirm the code selected, the pilot should:
(a) verify the Mode A code setting on the transponder;
(b) reselect the assigned code if necessary; and
(c) confirm to ATC the setting displayed on the controls of the transponder.
SERA.13010 Pressure-altitude-derived information
(a) When the aircraft carries serviceable Mode C equipment, the pilot shall continuously
operate this mode unless otherwise dictated by ATC.
(b) Unless otherwise prescribed by the competent authority, verification of the pressure-
altitude-derived level information displayed to the controller shall be effected at least once
by each suitably equipped ATC unit on initial contact with the aircraft concerned or, if this is
not feasible, as soon as possible thereafter.
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Centrik Regulations Team note: This item was due to be amended by CIR (EU) 2020/469 however, the
applicability date for the changes fell after the EU exit date. Therefore, the amendments did not enter
UK Law and were not applied to this item.
SERA.13010(b) GM1 Pressure-altitude-derived information
ERRONEOUS LEVEL INFORMATION
(a) If the displayed level information is not within the approved tolerance value or when a
discrepancy in excess of the approved tolerance value is detected subsequent to
verification, the pilot should be advised accordingly and requested to check the pressure
setting and confirm the aircraft’s level.
(b) If, following confirmation of the correct pressure setting, the discrepancy continues to exist,
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